Prior to the present invention, it is generally well known in the railway industry, that the throttle controller assemblies used in a railway type locomotive are almost exclusively of the electro-mechanical type. Engine control information originating in the engineer's console as handle positions is converted to electrical signals by mechanical switches, and thence conveyed to the throttle controller, which applies electrical signals to the trainlines which control the locomotive. For remote operation by radio link from a lead locomotive to a slave locomotive, it has been necessary to utilize a dedicated boxcar with the slave locomotive to accommodate radio equipment and relays. The information transmitted from the lead locomotive to the slave locomotive has been rigorously defined by hardware structure. Likewise, diagnostic information sent from the slave locomotive back to the lead locomotive has been rigorously defined by hardware structure. In the prior art, the diagnostic information has consisted of (1) hot engine, (2) brake warning, (3) wheel slip, and (4) ground fault. No method has hitherto been available for transmitting diagnostic information concerning the status of the trainlines fro the slave locomotive back to the lead locomotive.
Likewise, no method has been available for adding new information to the information transmitted from the lead locomotive to the slave locomotive, or back from the slave locomotive to the lead locomotive.
It can be seen from the above discussion of the prior art electro mechanical type throttle controller assemblies, presently used in the railroad industry that there is an unfilled need which exists in the modern railroad industry for an improved communications protocol which will enable feedback of diagnostic information concerning trainline status from the throttle controller to the remote host computer.
There is also a need to provide a convenient means in the future for adding additional information for transmission from the remote host computer to the throttle controller, and from the throttle controller to the remote host. It is evident that this need has been addressed by the present invention.